Upload
clifford-walters
View
221
Download
0
Embed Size (px)
Citation preview
TEC
Trilateral Euregio ClusterInstitut für Plasmaphysik Assoziation EURATOM-Forschungszentrum Jülich
21st IAEA Fusion Energy Conference, 16 - 21 October 2006 , Chengdu, China
Influence of the Dynamic Ergodic Divertor on TEXTOR
Discharges
K.H. Finken, Y. Xu, S.S. Abdullaev, M. Jakubowski, M. Lehnen, M. F. M. de Bock, S. Bozhenkov, S. Brezinsek, C. Busch,
I.G.J. Classen, J.W. Coenen, D. Harting, M. von Hellermann, S. Jachmich, R.J.E. Jaspers, Y. Kikuchi, A. Krämer-Flecken, M. Mitri,
P. Peleman, Pospieszczyk, D. Reiser, D. Reiter, U. Samm, D. Schega, A.O. Schmitz, S. Soldatov, B. Unterberg, M. Van Schoor, M. Vergote,
R.R. Weynants, R. Wolf, O.Zimmermann, and the TEXTOR Team
TEC
Trilateral Euregio ClusterInstitut für Plasmaphysik Assoziation EURATOM-Forschungszentrum Jülich
21st IAEA Fusion Energy Conference, 16 - 21 October 2006 , Chengdu, China
#94809
LFS HFS DED topics:
Helical divertor
Field line and plasma topology
Impurity shielding
Field line penetration
Interaction with MHD
TEC
Trilateral Euregio ClusterInstitut für Plasmaphysik Assoziation EURATOM-Forschungszentrum Jülich
21st IAEA Fusion Energy Conference, 16 - 21 October 2006 , Chengdu, China
Outline:
• Introduction to DED
• Effect of the perturbation field on ELMs
• Improved confinement by DED
•Turbulence reduction by DED
• Summary
TEC
Trilateral Euregio ClusterInstitut für Plasmaphysik Assoziation EURATOM-Forschungszentrum Jülich
21st IAEA Fusion Energy Conference, 16 - 21 October 2006 , Chengdu, China
16 DED coils
Max. current per coil: 15 kA
DC and AC up to: 10 kHz
TEC
Trilateral Euregio ClusterInstitut für Plasmaphysik Assoziation EURATOM-Forschungszentrum Jülich
21st IAEA Fusion Energy Conference, 16 - 21 October 2006 , Chengdu, China
m = 6, n = 2
m = 12, n = 4
m = 3, n = 1
Base modes for DED operation
TEC
Trilateral Euregio ClusterInstitut für Plasmaphysik Assoziation EURATOM-Forschungszentrum Jülich
21st IAEA Fusion Energy Conference, 16 - 21 October 2006 , Chengdu, China
H-mode characterization and ELM suppression by DED-field
TEC
Trilateral Euregio ClusterInstitut für Plasmaphysik Assoziation EURATOM-Forschungszentrum Jülich
21st IAEA Fusion Energy Conference, 16 - 21 October 2006 , Chengdu, China
~ 500 Hz
ALTH - drop
DED
0 0.5 1 1.5 2 2.5 30
5
10
15
H /
a.u
.
TEXTOR # 97315
2.5 2.505 2.51 2.515 2.520
5
10
time / s
H /
a.u
.
Characterization of H-modeBasic scenario: Ip= 240 kA/ Bt= 1.2 T-1.4 T, plasma shifted
to HFS (R=1.68m / a=0.4m)
TEC
Trilateral Euregio ClusterInstitut für Plasmaphysik Assoziation EURATOM-Forschungszentrum Jülich
21st IAEA Fusion Energy Conference, 16 - 21 October 2006 , Chengdu, China
Power threshold about twice the L-H threshold in divertor tokamaks – “typical” for limiter H-modes
4 5 6 7 8 9 10x 10
5
0.8
1
1.2
1.4
1.6
1.8
2
P sep /
W x
10
6
PL-H thresh, IAEA96 / W
o no DED
+ with DED
# 97300/1, 97312/14/15, # 98296, 98491, 99595
with ELM signature w./o. ELM signature
"dithering"
continued ELM - signature over 1s
# 97314
# 98491 (L-H transition)
Predictive RITM code calculations for 1.3 MW heating power and
H/ (H+D) = 40%
and TEXTOR data
D. Kalupin,
M. Tokar
TEC
Trilateral Euregio ClusterInstitut für Plasmaphysik Assoziation EURATOM-Forschungszentrum Jülich
21st IAEA Fusion Energy Conference, 16 - 21 October 2006 , Chengdu, China
1 1.2 1.4 1.6 1.8 20
500
1000
1500
N
EL
M /
Hz
ELM frequencies TEXTOR limiter H-mode
TEC
Trilateral Euregio ClusterInstitut für Plasmaphysik Assoziation EURATOM-Forschungszentrum Jülich
21st IAEA Fusion Energy Conference, 16 - 21 October 2006 , Chengdu, China
Evolution of edge pressure HFSTEXTOR # 97315 (thermal He beam)
R= 1.3 m
L-H –transition
H- L –transitionwith DED
TEC
Trilateral Euregio ClusterInstitut für Plasmaphysik Assoziation EURATOM-Forschungszentrum Jülich
21st IAEA Fusion Energy Conference, 16 - 21 October 2006 , Chengdu, China
2.2 2.4 2.6 2.8 30
1
2TEXTOR # 97315
D /
a.u
.
2.2 2.4 2.6 2.8 30
5
10
15
I DE
D /
kA
2.2 2.4 2.6 2.8 3-1000
0
1000
v /
m/s
(C
III)
time / s
L-H transition DED induced back transition
ELM mitigation in 12/4 base mode
ELM suppression starts at 3 kA
TEC
Trilateral Euregio ClusterInstitut für Plasmaphysik Assoziation EURATOM-Forschungszentrum Jülich
21st IAEA Fusion Energy Conference, 16 - 21 October 2006 , Chengdu, China
ELM mitigation in 12/4 base mode
DED threshold:3 kA
TEC
Trilateral Euregio ClusterInstitut für Plasmaphysik Assoziation EURATOM-Forschungszentrum Jülich
21st IAEA Fusion Energy Conference, 16 - 21 October 2006 , Chengdu, China
2 2.2 2.4 2.6 2.8 3 3.2 3.4 3.6-1
0123
TEXTOR # 98296 (Ip = 250 kA / BT = 1.4 T, R= 1.72 m, a= 0.44 m)
2 2.2 2.4 2.6 2.8 3 3.2 3.4 3.60
2
4x 10
6
Pto
t / W
2 2.2 2.4 2.6 2.8 3 3.2 3.4 3.60
5
D /
a.u
.
2 2.2 2.4 2.6 2.8 3 3.2 3.4 3.60
1
2
time / s
Te /
a.u
. (
~0.
9)
ne / 1019 m-3
IDED
/ kA (AC 1 kHz)
ELM mitigation in AC 3/1 base mode
TEC
Trilateral Euregio ClusterInstitut für Plasmaphysik Assoziation EURATOM-Forschungszentrum Jülich
21st IAEA Fusion Energy Conference, 16 - 21 October 2006 , Chengdu, China
Improvement of energy confinement during H-mode modest some reduction of energy confinement with DED
0.015 0.02 0.0250.015
0.016
0.017
0.018
0.019
0.02
0.021
0.022
0.023
0.024
0.025E / s
E, ITERH89P / s
w./o. ELM signature with ELM signature
o no DED
+ with DED
H89=1
H89= 1.25
TEXTOR # 97300/1, 97312/14/15
R= 1.68m
TEC
Trilateral Euregio ClusterInstitut für Plasmaphysik Assoziation EURATOM-Forschungszentrum Jülich
21st IAEA Fusion Energy Conference, 16 - 21 October 2006 , Chengdu, China
Confinement change with DED in
m/n = 6/2 base mode
TEC
Trilateral Euregio ClusterInstitut für Plasmaphysik Assoziation EURATOM-Forschungszentrum Jülich
21st IAEA Fusion Energy Conference, 16 - 21 October 2006 , Chengdu, China
Best conditions have been observed for
• strongly inward shifted plasmas
• low density plasmas, low collisionality
• Co-NBI heating
• Ip = 310 kA; Bt = 1.9 T
• IDED = 7.5 kA
TEC
Trilateral Euregio ClusterInstitut für Plasmaphysik Assoziation EURATOM-Forschungszentrum Jülich
21st IAEA Fusion Energy Conference, 16 - 21 October 2006 , Chengdu, China
Stepwise density increase during DED-ramps
TEC
Trilateral Euregio ClusterInstitut für Plasmaphysik Assoziation EURATOM-Forschungszentrum Jülich
21st IAEA Fusion Energy Conference, 16 - 21 October 2006 , Chengdu, China
Density profile Density time trace
TEC
Trilateral Euregio ClusterInstitut für Plasmaphysik Assoziation EURATOM-Forschungszentrum Jülich
21st IAEA Fusion Energy Conference, 16 - 21 October 2006 , Chengdu, China
pressure time trace
TEC
Trilateral Euregio ClusterInstitut für Plasmaphysik Assoziation EURATOM-Forschungszentrum Jülich
21st IAEA Fusion Energy Conference, 16 - 21 October 2006 , Chengdu, China
Comparison of pressure profiles for discharges with and without DED
(from Thomson scattering)
Ne Ne*Te
TEC
Trilateral Euregio ClusterInstitut für Plasmaphysik Assoziation EURATOM-Forschungszentrum Jülich
21st IAEA Fusion Energy Conference, 16 - 21 October 2006 , Chengdu, China
3.75kA 4/2
9/4
5/2
FP = +80V
FP = +120V
6/2
Plasma rotation
Poloidal rotation CIII
Heat pattern and
electric potential
Related effects
TEC
Trilateral Euregio ClusterInstitut für Plasmaphysik Assoziation EURATOM-Forschungszentrum Jülich
21st IAEA Fusion Energy Conference, 16 - 21 October 2006 , Chengdu, China
Field line structure at density step
q=2.0 island
Poincaré plot Laminar plot
Starting ergodization of q=2 surface
TEC
Trilateral Euregio ClusterInstitut für Plasmaphysik Assoziation EURATOM-Forschungszentrum Jülich
21st IAEA Fusion Energy Conference, 16 - 21 October 2006 , Chengdu, China
Effect of the DED on turbulence
TEC
Trilateral Euregio ClusterInstitut für Plasmaphysik Assoziation EURATOM-Forschungszentrum Jülich
21st IAEA Fusion Energy Conference, 16 - 21 October 2006 , Chengdu, China
Turbulence-probe3 strokes during one discharge
Effect of the DED on turbulence
TEC
Trilateral Euregio ClusterInstitut für Plasmaphysik Assoziation EURATOM-Forschungszentrum Jülich
21st IAEA Fusion Energy Conference, 16 - 21 October 2006 , Chengdu, China
Turbulence-probe head (RS-probe)
“Reynolds stress probe”:o measures:
• floating and plasma potential• electron temperature• electron density and particle flux
o main feature:• small pins dedicated to measurefluctuations of poloidal and radial velocity => Reynolds stress Zonal flows
o min radius: 42 cm (217 cm)
Boron-nitride body(isolator)
Tungsten pins(d = 1-2 mm)
, , , , , , , , , , , ( , )e e fl pl r e e r rn T E n T E E v v S k
TEC
Trilateral Euregio ClusterInstitut für Plasmaphysik Assoziation EURATOM-Forschungszentrum Jülich
21st IAEA Fusion Energy Conference, 16 - 21 October 2006 , Chengdu, China
Ergodic zonea=45.7cm
Equilibrium profiles (6/2 DED)
Vf Te
Before DED DED ramp DED plateau
ne
r (cm)r (cm)
a=45.7cm
Er
TEC
Trilateral Euregio ClusterInstitut für Plasmaphysik Assoziation EURATOM-Forschungszentrum Jülich
21st IAEA Fusion Energy Conference, 16 - 21 October 2006 , Chengdu, China
Turbulence with / without DED in 3/1 DED~
in 6/2 DED~
Before DED DED ramp DED plateau
S(f)
a
r (cm)
lc (cm)
lcr (cm)
Ergodic zone
Coherent modes reduced
Size of turbulent cells reduced
Inward flux with DED
TEC
Trilateral Euregio ClusterInstitut für Plasmaphysik Assoziation EURATOM-Forschungszentrum Jülich
21st IAEA Fusion Energy Conference, 16 - 21 October 2006 , Chengdu, China
Summary
Confinement improvements have been observed for some plasma / DED conditions.
Best conditions were found for strongly heated low density plasmas shifted strongly towards the HFS (DED).
Improvement has a resonance character with respect to q(a) and the DED-current.
On TEXTOR, a limiter H-mode has been obtained.
The ELMs were reduced at moderate ergodization levels.
12/4 and AC 3/1 base modes have been applied successfully.
The energy confinement is slightly reduced by DED.
TEC
Trilateral Euregio ClusterInstitut für Plasmaphysik Assoziation EURATOM-Forschungszentrum Jülich
21st IAEA Fusion Energy Conference, 16 - 21 October 2006 , Chengdu, China
Summary continued
Probe measurements:
Strong effect of DED on equilibrium values of F(r) and Er.
Turbulent flux reverses sign.
Size of large turbulent structures reduced.
Coherent modes strongly reduced.